Tesla Model S 4WD launched

A new four-wheel-drive version of the Model S sedan has joined Tesla's line up. The new 'D' versions have an electric motor on each axle, as against the rear axle driven current line-up.

The addition of a motor on the front axle will boost traction and improve stability, consequently widening the car's appeal in markets where inclement weather and poor road conditions are frequent.

There are three variants of the four-wheel-drive Tesla Model S available – the 60D, 85D and P85D. The all-wheel-drive Teslas may command a premium of $4000 (approximately Rs 2.45 lakh) over rear-drive models.

Tesla boss Elon Musk said: "What makes this unique and better than previous all-wheel-drive cars is that you can dynamically shift the power from front to rear at the millisecond level; you can very quickly adjust torque – more than is possible than with a mechanical system.

"With all all-wheel-drive systems out there, they're less efficient. In the case of the Model S, because we can shift the power so quickly, we can be constantly at the most efficient point for the individual motors, and overcome the weigh penalty. Literally everything improves."

The 60D and 85D's electric motors produce 188bhp and 25.02kgm, resulting in a combined 376bhp and 50.05kgm. The 60D variant has a claimed top speed of 201kph, a 0-97kph time of 5.7sec, and a range of 362km at an average of 105kph. The higher-performance 85D delivers 250kph, 5.2sec and 475km respectively.

What's most notable, however, is the new flagship version – badged the P85D. It packs significantly more powerful motors, with the front electric motor producing 221bhp and 34kgm, the rear 470bhp and 61.2kgm. That means a net output of 691bhp and 95kgm.

Consequently, the P85D delivers supercar-like acceleration figures, in part thanks to the ability of an electric motor to produce maximum torque from zero rpm; Tesla claims it can dispatch the 0-97kph sprint in 3.2sec, as fast as a Ferrari 458 Speciale, and complete the standing quarter mile in 11.8sec.
Despite its performance credential, the P85D is also claimed to have a range, at a constant 105kph, in the region of 443km.

Additionally, both the 60D and 85D perform better in all areas – including range – than their two-wheel-drive equivalents, despite an 80kg weight penalty.

The P85D version is much faster than its rear-drive alternative, but its range is ten miles less – presumably because of an additional 132kg incurred by larger motors and the addition of the four-wheel-drive system. It does boast a 50/50 weight distribution, however, and can deliver an accelerative force of 1G.

Musk added: "This car is nuts. It's like taking off from a carrier deck; just bananas. It's like your own personal roller coaster."

During the presentation at which the new D variant was revealed, Tesla also showcased a semi-autonomous mode for the Model S. Thanks to the use of myriad cameras and sensors, it permits the car the ability to change lanes of its own accord when a driver indicates, regulate its speed according to the signposted limits, self-park and perform emergency stops.